Pushed to the brink of suicide by the son they loved so much

One evening in a rare, brief break from the chaos of looking after our severely autistic son, my husband, Derek, and I caught a glimpse of a TV nature documentary.

On the screen, a cuckoo fledgling was gradually taking over the nest of two sparrows who were working themselves to exhaustion to feed the young interloper. As the cuckoo grew bigger, more demanding and aggressive, the sparrows became more depleted and careworn.

I remember looking at Derek: we both shared the same unspoken thought. This was what our lives had become.

Giles, our handsome, beloved only child — my longed-for son, born after a succession of miscarriages — was so troubled by his condition that there were times when I’d cower in a corner as he rained blows down on my head.